1. Land use features and administrative framework | 13 Introduction to the SFRL 1.5 Laws and policies in relation to land use in the SFRL TABLE 1.5: Land related laws and policies and their implementing agencies Laws/Policies/Plans/ Programmes Agencies Laws • The Forest Ordinance No. 16 of 1907, and its subsequent amendments, including Act No. 23 of 1995 and Act No. 65 of 2009 • FD • The Fauna and Flora Protection Ordinance No. 2 of 1937, and subsequent amendments including Act No. 49 of 1993 and Act No. 22 of 2009 • DWC • Local Authorities Laws namely Municipal Councils Ordinance • LAs: MCs • Urban Councils Ordinance and Pradheshiya Sabha Act • LAs: PS • Land Development Ordinance No 19 of 1935 and Subsequent amendments • LCGD • Land Grants (Special provisions) Act No 43 of 1978 • LCGD • State Lands Ordinance No. 8 of 1947 (formerly Crown Lands Ordinance LO) • LCGD • State Land (Recovery of Possession) Act No,7 of 1979 • LCGD • Land Acquisition Act 09 of 1950 • MoL, with power delegated to DS. • Land Settlement Ordinance No 20 of 1931 • LSD • Title Registration Act No 21 of 1998* • LSD • SD • RGD • LCGD, MoL • Land Reform Law No 1 of 1972 • LRC • Urban Development Authority Act Law No 41 of 1978 • UDA • Agrarian Development Act 46 of 2000 • DAD • The National Environmental Act No.47 of 1980 and 1988 • Soil Conservation Act of 1951 and Amendments, • CEA • DoI Policies • The National Land Use Policy of 2007 (at present being revised) • LUPPD • National Policy on Protection and Conservation of Water Sources and their Catchments and Reservations in Sri Lanka 2014 • MoL, CEA, SD, WRB, ID and many other agencies Details of laws and policies are in Appendix 1-B
1. Land use features and administrative framework | 14 Introduction to the SFRL
Climate 2 © J D S Dela
2. Climate | 16 Introduction to the SFRL 2. Climate 2.1 Rainfall Spatial Variation The main source of water in the SFRL is rainfall, which feeds the rivers and streams that provide water for drinking and other domestic uses, agriculture, and power generation. Rainfall is also the primary source of soil moisture, streamflow, and groundwater in the landscape. As the SFRL is located mainly in the southwestern area of the wet zone, it receives a high rainfall year-round with no pronounced droughts. This is due to the interception of moisture-laden South-West monsoon winds by the central highlands, resulting in a separation of the ever-wet Southwestern region from the dryer area in the island at the 2000m isohyet.1 As a result, the SFRL receives a high mean annual average rainfall that varies generally from about 2000 mm to 4500 mm in different locations. The spatial variation of mean annual rainfall in the SFRL over the period 1986 to 2019 (Figure 2.1)2 shows the lowest rainfall in the Kolonna and Godakawela DSDs in the eastern region of the landscape where it grades into the intermediate zone. The highest rainfall is in the wet zone DSDs of Kalawana, and Neluwa in the south and central areas of the SFRL. 1 Manchanayake E P and Madduma Bandara C M (1999). Water Resources of Sri Lanka. National Science Foundation, Sri Lanka. 2 Source: Rainfall data 1986-2019 from rainfall gauging stations maintained by the Department of Meteorology and other relevant organizations in and near the SFRL. The gauging stations are mapped in Figure 2.1. Figure 2.1: Spatial rainfall variation within the SFRL during 1986-2019 (Source: Data from the Department of Meteorology 1986-2019)
2. Climate | 17 Introduction to the SFRL Temporal variation Annual variability The rainfall intensities at the Kudawa gauging station, which receives the highest rainfall in a year, show that the rainfall intensity at that location expected to occur once in 2 years is about 151 mm/day (estimated based on rainfall data from 1979 to 2011). Higher rainfalls expected to occur once in 5 years and 10 years are about 217 mm/day and 271 mm/day, respectively (i.e. these rainfalls have 20% and 10% probabilities of occurring once a year). Variation of annual total rainfall at Halwatura and Mawarella Estate gauging stations are observed to be high compared to the other stations. Annual total rainfalls at Kudawa, (Kalawana DSD) Pelawatta (Walallawita DSD) and Ratnapura (Ratnapura DSD) show least variation. Seasonal variability Much of the precipitation is received during the South-West monsoon period from May to September. Rainfall from the North-East monsoon from December to February is lower (Table 2.1), because of the rain shadow caused by the island's central mountains. Rains are also received throughout the two intermonsoonal seasons from April-May and October-November (Table 2.1). Tropical cyclones accompanied by heavy rains are common from June to November, with a peak in October.3 TABLE 2.1: Seasonal variation of mean rainfall received in the SFRL at nine different gauging stations (mm) Rainfall gauging station 1st intermonsoon (Mar - Apr) SW monsoon (May-Sep) 2nd intermonsoon (Oct - Nov) NE monsoon (Dec - Feb) Deniyaya 697.6 1409.2 836.2 581.2 Depadena 587.1 1435.1 780.3 484.7 Halwatura 576.7 2053.6 1061.8 516.4 Hiniduma 682.6 1847.3 1080.1 717.0 Horagoda Estate 583.4 1853.5 854.5 553.0 Kudawa 663.0 2232.1 956.2 571.7 Pelawatta 669.5 2075.5 1011.6 699.8 Ratnapura 562.5 1821.6 834.7 469.4 Wellandura 442.2 1211.9 630.8 416.4 Source: Department of Meteorology data 1979 to 2011 Monthly variability Analysis of mean monthly rainfall variation from 1986 to 2019 at nine rainfall gauging stations in the landscape (Figure 2.2) shows highest rainfall from April to June during the South-West monsoon, and from September to November during the second inter-monsoonal period. Thus, irrigated agriculture, in general, shows a positive relationship with rainfall in the SFRL during the South-West monsoon or the Yala season. However, highlands are liable to be affected sometimes when low rainfalls are received during this period because there are only minor irrigation schemes in the area, and they are easily affected by low rainfall. Similarly, continuous heavy rainfall during the South-West monsoon season and second inter-monsoon season destroys more crops in the lowland areas of the SFRL. 3 Annual total rainfalls at nine gauging stations from 1986 to 2019 with annual average values, standard deviations, coefficient variations, maximum and minimum annual rainfalls are in Appendix 2-A.
2. Climate | 18 Introduction to the SFRL Trends in annual variation Rainfall trends at three of the nine gauging stations, in or near the SFRL show an increase, but six DSDs record a mild decrease (Table 2.2). There is also no clear spatial pattern for these trends: there is an increasing trend at the stations towards the southwestern part of the SFRL (Kudawa, Horagoda Estate and Hiniduma) while all the other stations show negative trends. 2.2 Climate and agro-ecology The agro-ecological zones within the SFRL are given in Figure 1.6 (section 1 land use). Rainfall and topographical variation in the SFRL have given rise to eight agro-ecological zones (namely: WU1, WM1a, WM1b, WL1a, WL2a, IM1c, IL1b and IL1c.), out of the 46 identified for the entire country (Annex 2.1). The mean monthly rainfall profiles of the agro-ecological zones within the SFRL are given in Table 2.3. TABLE. 2.2: Rainfall trends in and around the SFRL Station Period Trend (mm/yr) Station Period Trend (mm/yr) Deniyaya 1986 2019 Negative -3.1 Depadena Group 1986 2019 Negative -9.6 Halwatura 1986 2019 Negative -3.2 Hiniduma 2000 2019 Positive 38.2 Horagoda Estate 1986 2015 Positive 11.7 Kudawa 1986 2019 Positive 1.8 Pelawatta 1986 2019 Negative -4.3 Ratnapura 1986 2019 Negative -3.3 Wellandura Estate 1986 2019 Negative -9.4 Figure 2.2: Analysis of mean monthly rainfall variation during 1986-2019 0 100 200 300 400 500 600 700 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Average monthly rainfall (mm) Rainfall gauging stations Deniyaya Depadena Halwatura Hiniduma Horagoda Estate Kudawa Mawarella Estate Pelawatta Ratnapura Wellandura Gauging station data with averages greater than 350mm monthly rainfall are depicted in dashed lines
Introduction to the SFRL 2. Climate | 19 TABLE 2.3: Characteristics of the agro-ecological zones Climatic Zone Agro-Ecological Region Value of Annual rainfall (mm) 75% Rainfall probability for respective regions (mm) DSDs within the zones Wet Zone Mid Country WM1a >3,300 WM1a: Half of Kalawana (where the Sinharaja forest Occurs. The upper part of Neluwa, and much of Kotapola, as well as small areas of Nivitigala, Godakawela, Kolonna, Pitabeddara and Palindanuwara. WL1a >3,200 WL1a: Much of Pitabeddara, Neluwa, Thawalama, Walallawita, Agalawatte, Palindanuwara, Bulathsinghala, Ayagama, Elapatha, Kalawana, Nivithigala and a small segment of Pelmadulla, Kahawatte and Kotapola. Up Country WU1 >3,100 WUI: Connected patch which covers a small area of Kalawana, Kahawatte, Godakawela, Kolonna, Kotapola Mid Country WM1b >2,900 WM1b: Patches in Ayagama, Elapatha, Kalawana, Nivithigala, Kahawatte, Godakawela. Low Country WL2a >2,400 WL2a: Kahawatte, Pelmadulla, Godakawela, northeast Nivithigala, Intermedia te Zone Mid Country IM2a >1,800 IM2a: Kolonna and Godakawela Low Country IL1c > 1, 300 IL1c: Small segment in Godakawela
Introduction to the SFRL 2. Climate | 20 Although much of the SFRL falls within the lowland wet zone having a high rainfall, it grades into the intermediate climatic zone at its northeastern end, and is spread over all three elevation zones of low, mid and up-country areas. The mid and low country wet zone areas experience well distributed heavy rainfall (2400-3300 mm/year). Accordingly, the Wet Zone agro-ecological regions WM1a, WL1a and WU1, which cover much of the SFRL, spans the DSDs of Bulathsinghala, Agalawatte and Walallawita. They receive a mean annual rainfall of >3310mm/year, with lowest rainfall in January and February and highest in May and June. Mid and low country intermediate zones (IL1b, IL1c, IM1c) show comparatively less rainfall (1100- 2000mm/year as well as greater mean monthly variability than the wet zone DSDs, with Kolonna being most water-stressed. Rainfall is highest in the intermediate zone areas during the October-November Intermonsoonal rains. 2.3 Temperature, wind speed, and humidity Monthly average temperature, wind speed, and relative humidity could only be collected for the SFRL from the Kudawa gauging station, so that these features may vary in other areas of the landscape. There is no gauging station within the Sinharaja Forest Reserve apart from a small station which is not in working order and the Morning Side station managed by the Wildlife Conservation Society-Galle. Figures 2.3 provides data 2015 to 2019.4 Temperature at the Kudawa station in the SFRL is constant over time, with an average of 26⁰C (range 25⁰-29⁰C), with the highest temperature from March to April, and the lowest in December. In general, the relative humidity varies between 77% and 90%. The average wind speed at this station varied from around 2.8 km/h to 9.9 km/h with a mode of 3.5 km/h. The area has on average light air (1 – 5 km/h) according to the Beaufort scale, and a light breeze (6 – 11 km/h) only. In general, the wind speeds are highest from June to September. 4 Data were collected from the “World Weather Online” site TABLE 2.3: Characteristics of the agro-ecological zones Climatic Zone Agro-Ecological Region Value of Annual rainfall (mm) 75% Rainfall probability for respective regions (mm) DSDs within the zones Low Country IL1b >1,100 IL1b: Small area of Kolonna Source: Agro-ecological Zone map in Sri Lanka, NRMC/DoA, 2003 and National Atlas 2007, SD
2. Climate | 21 Introduction to the SFRL 2.4 Evaporation Pan evaporation recorded at three stations within the SFRL boundary, namely Ratnapura, Agalawatte and Batewela stations, are shown in Figure 2.4. The monthly Pan Evaporation at the above mentioned three stations is given in Appendix 2-B. The Pan values for Ratnapura, Agalawatte and Batawela are respectively 1013.5 mm, 936.9 mm, and 1438.5 mm; those for Agalawatte and Batawela show long term average values (from 2013 to 2017), while Batawela Figure 2.3: Monthly average of temperature, wind speed and relative humidity at Kudawa Figure 2.4: Pan evaporation from gauging stations in and around the SFRL (Source: Hydrological Annuals of the Department of Irrigation, Sri Lanka, 2013 -2017)
2. Climate | 22 Introduction to the SFRL values are for the 2016/17 water year. Evaporation is low in the areas that receive high rainfall. As such, the evaporation loss from Agalawatte, where rainfall is high, was low compared with Ratnapura and Batawala. The latter, which receives a relatively low rainfall has a high evaporation loss. DSDs in the SFRL such as Pelmadulla DSD and Ratnapura DSD can, therefore, be expected to have high pan evaporation, while DSDs such as Agalawatta DSD could be expected to have low pan evaporation. 2.5 Impact of climate change The assessment of the impact of climate change and its vulnerability and risks on natural disasters and anticipated effects on the key economic sectors is very significant for the preparation and implementation of the SFR-LMP. The key economic sectors that would be affected by climate change impacts can be broadly identified as: • Agriculture and plantations • Biodiversity and ecosystem services • Water for domestic, agricultural and industrial use • Human settlements and housing • Urban development and economic infrastructure • Human health and well-being. The world is currently at 1.10 C of warming. Research released during the recent COP 26 indicates that even with the current Nationally Determined Contributions or NDCs it adds up to 2.40 C of temperature rise by the end of the century. However, crossing the 2 degrees threshold will put over 1 billion people under extreme heat stress; bleach 99% of coral reefs; double the extinction of plant species, and intensify the melting of sea ice in summer by 10 times, fueling up to 6m of sea-level rise in vulnerable parts of the world. To many countries it means a “death sentence”. Sri Lanka, an island nation, can be expected to be seriously affected. The projected impact of climate change on the frequency and severity of natural hazards, and their impact on economic sectors within the SFRL are dealt with in section 13 (Natural Hazards). This section deals with trends in temperature rise and variability of rainfall (Box 2.1) that can be expected to affect the SFRL. BOX 2.1: IMPACTS OF CLIMATE CHANGE ON THE WEATHER IN SRI LANKA Increasing temperature • Air temperature in Sri Lanka has increased by 0.640C over the past 40 years and 0.970C over the last 72 years, which revealed a trend of 0.140C per decade. However, the assessment of a more recent time band of 22 years has shown a 0.450C increase over the last 22 years, suggesting a rate of 0.20C per decade. • Consecutive dry days are increasing in the Dry and Intermediate Zones. • Ambient temperature (both minimum and maximum) has increased. • The number of warm days and warm nights has increased, while the number of cold days and cold nights has decreased. Rainfall variability • The precipitation patterns have changed, but conclusive trends are difficult to establish. • A trend for rainfall decrease has been observed historically over the past 30-40 years, but this is not statistically significant. • There is a trend for the increase of one day heavy rainfall events. • An increase in the frequency of extreme rainfall events is anticipated, which would lead to more floods. Drought • The increased frequency of dry periods and droughts is expected. • The general warming trend is expected to increase the frequency of extreme hot days. Source: Department of Meteorology, Sri Lanka, provided for preparation of this report (2010).
2. Climate | 23 Introduction to the SFRL Rainfall variability A clear impact of climate change on the weather patterns of Sri Lanka is increased rainfall variability, with a trend for the increase of one day heavy rainfall events. Figure 2.5 suggests that the SFRL has not experienced a major impact after one-day heavy rainfall (i.e. >30mm/day) events during 1980-1999 and 2000- 2019. However, heavy rainfall for three consecutive days, amounting to >90 mm/day experienced during the above period has had an impact on the northern DSDs of the SFRL.5 Figure 2. 6 shows the heavy rainfall received over 24 hours on 21 May 2018 with affected districts and proposed prioritization for a response. 5 Source: S. Premalal, SDLG/UNDP, 2021 overlaid with the SFRL boundary Figure 2.5: Impacts of rainfall on a single day and over 3 consecutive days Source: Premalal S, SDLG/UNDP, 2021 overlaid with the SFRL boundary
2. Climate | 24 Introduction to the SFRL Rise in temperature Table 2.4 projects a very serious temperature rise in Sri Lanka from 2020 to 2090. According to Figure 2.7, this can have serious impacts on the SFRL under a business as usual scenario with temperatures rising between 0.90 - 1.00 C in the 2060s, and between 1.00 - 2.00 C in the 2080s. TABLE 2.4: Projected increase of temperature in Sri Lanka (2020-2090) Source: Darshika, et.al. 2018. Emission Level 2020-2040 2040-2060 2070-2090 Moderate Emission (RCP 4.5) 1.00C 1.30C 1.90C High Emission (RCP 8.5) 1.30C 1.90C 2.70C The annual average temperature changes over the 2060s and 2080s in Sri Lanka are presented in Figure 2.7, which indicates a significant temperature rise in the SFRL. The assessment of climate change impact on indigenous fauna is continuing, but provisional range restriction maps for proxy species that represent the fate of other wet zone endemics reportedly indicate that the SFRL may well be a refuge for many endemic species in the future (personal communication, Dr Suranjan Fernando, ESA project of the MoE). Figure 2.6: Extreme rainfall received during a 24-hour period (Source: Department of Meteorology Department, unpublished data provided for the SFR-LMP)
2. Climate | 25 Introduction to the SFRL 2.6 Laws and policies in relation to climate in the SFRL TABLE 2.5: Hazards related laws and policies and their implementing agencies Laws/Policies/Plans/ Programmes Agencies Laws • Meteorology Act enacted in Oct 1948 Observation Network consists of 22 Meteorology Stations managed by MD, and 42 Agrometeorology stations by various Govt. & statutory institutions, 350 rain gauging stations • The National Environmental Act No.47 of 1980 and 1988 • Central Environmental Authority Policies • The National Environment policy of 2003 • MoE • National Policy on Climate Change 2012 • MoE Figure 2.7: Annual Average Temperature of Sri Lanka and Projected Temperature Changes in 2060’s and 2080’s (Source: HSEP SL-ADB, 2018).
2. Climate | 26 Introduction to the SFRL
Landscape, topography, and geology 3 © J D S Dela
3. Landscape, topography, and geology | 28 Introduction to the SFRL 3. Landscape, topography, and geology 3.1 Topographical features Much of the Sinharaja Forest Range Landscape (SFRL) falls within the middle peneplain of Sri Lanka. It spreads onto the Rakwana massif in the southwest of Sri Lanka, which is similar to the southern cliff of the hill Country, but much smaller in scale and lower in height.1 The road from Rakwana to Deniyaya runs within the SFRL between the Walankanda and Sinharaja forest complexes, and crosses the escarpment at the only break in it for miles. The mountainous areas of the SFRL rising to the northeastern segment of the landscape include Beralagala, Gongala, Kiribathgala, and Kabaragala. In addition, there are many isolated mountain outcrops towards the outer areas of the landscape (Figure 3.1). The landforms in the mountainous areas consist of steeply dissected hilly and rolling terrain that were subject to landslides in the past and in recent years (Section 13), and are flat to undulating terrain towards the western part of the landscape. The region is also characterized by long, parallel strike ridges and valleys that run in a northwestern and southeastern direction, giving rise to a distinctive dense pattern of narrow flat valleys separated by ridges with gentle dip slopes and steep scarp slopes. 1 Cooray, P.G. (1984). An Introduction to the geology of Sri Lanka (Ceylon). National Museums of Sri Lanka, Colombo. Figure 3.1: The topography and elevation of the SFRL
3. Landscape, topography, and geology | 29 Introduction to the SFRL Relief The SFRL grades from an elevation of 20 msl to 1367 msl (Figure 3.1). The highest areas of the SFRL occur at the eastern end of the Kalawana DSD, and spreads into the adjacent Kolonna and Godakawela and DS Divisions at their boundaries in the landscape. Similarly, on the western side of the SFRL, the land is lower and flatter, especially along paddy tracts and flood plains. The more low-lying areas in the southern, southwestern, and northwestern areas consist of flat, undulating and rolling terrain. Several peaks rise from the SFRL reaching above 3,500 feet/1066 m.1 Notable peaks and escarpments are Beralagala (4,545ft), Gongala (4,416ft), Sooriyakanda (4,300ft) and Abbey Rock (4,268ft). A series of high plains such as the Handapanella Plains and the Thangamale Plains are also found in the highest parts of the Rakwana massif at a general elevation of 3,500ft/1066m to 4,000ft/1220m.1 More than half the area of the SFRL is above 300m (from mean sea level) elevation category, which is considered as “The Central Fragile Zone” of Sri Lanka under the National Physical Plan 2050 Sources: National Physical Planning Policy & The Plan 2017 – 2050, NPPD 2019 BOX 3.1: TOPOGRAPHICAL AND GEOLOGICAL FEATURES OF TWO FORESTS IN THE SFRL The Sinharaja National Heritage Wilderness Area (NHWA) This forest has unique geological features, particularly due to the presence of a distinctive zone of basic rocks referred to as the “Sinharaja Basic Zone” which extends across the Sinharaja NHWA from Denuwakanda (in the SFRL) to way beyond: about 50 miles north up to Labugama. These rocks have given rise to an aero-magnetic anomaly due to a relatively high magnetic intensity, by the presence of magnetite which forms the main component of basic rocks. This is suspected to be the cause of “desilication”, resulting in “gem–fields in the surrounding region (FD, 1986). This forest also lies within the transition zone of two important groups of rock types in the island, the Southwestern group and the Highland group. The common rock types in the reserve are khondolites, other metasedimentary rocks, and charnockite gneisses of the Highland Series, and metasediments, charnockite gneisses and other rock types of the Southwestern group. (Source: FD1986, 1993; Cooray, P.G. 1984;1 and De Zoysa and Raheem, 1990) The Dellawa Forest The Dellawa forest which forms the southern buffer zone of the Sinharaja Biosphere Reserve lies in a geological transition zone, underlain by highly metamorphosed Precambrian rocks of the Highland series; comprising predominantly gneiss, quartzite and crystalline lime stone. The forest provides protection against soil erosion that could occur in its highly dissected terrain. A series of discontinuous North-West and South-East oriented ridge lines dominate the reserve. The steep slopes in this forest have a mean value of 28%. Vertical cliffs occur to the North-West of the reserve, and the centre slopes are usually in excess of 60%. Altitudes range from 300m in the valley bottoms to about 790m in the highest peak. Source: IUCN, 1995; FD (1986). Conservation Plan for the Sinharaja Forest. (unpublished); IUCN (1993). Management Plan for the Conservation of the Sinharaja Forest (Phase III) (unpublished); De Zoysa, N.D. and Raheem, R. (1990). Sinharaja: A Rain Forest in Sri Lanka. March for Conservation. Colombo; Cooray, P.G. (1984). An Introduction to the Soils of Sri Lanka (Ceylon). National Museums of Sri Lanka, Colombo. 1IUCN (1995). Dellawa Conservation Forest : The Management Plan (unpublished) 1 IUCN (1995). Dellawa Conservation Forest : The Management Plan (unpublished)
3. Landscape, topography, and geology | 30 Introduction to the SFRL Slope As shown in Figure 3.2, slope within the SFRL has considerable steep terrain (>200 ) where most of the area is covered with forest lands, while much of the western part is flat land (0-150 ) with flood plains. Figure 3.3: Percentage of different slope classes in the DSDs of the SFRL 0 5000 10000 15000 20000 25000 30000 35000 40000 45000 Ayagama Elapatha Nivithigala Kalawana Kahawatta Pelmadulla Godakawela Kolonna Palindanuwara Agalawatte Bulathsinghala Walallawita Neluwa Thawalama Kotapola Pitabeddara Area (ha) Divisional secratariat divisions 0 - 8% 8-16% 16 - 30% 30 - 60% >60% (Slope classes) Figure 3.2: Distribution of different slope classes in the Sinharaja Forest Range Landscape (SFRL)
3. Landscape, topography, and geology | 31 Introduction to the SFRL Over 44 % of the land area in the SFRL (107,732 ha) falls within the slope range of 0 – 8%. Most of these lands are in 10 DSDs, namely: Kalawana, Bulathsinghala, Godakawela, Kotapola, and Pelmadulla, Neluwa, Kolonna Elapatha, Kahawatta, Agalawatte where these flat lands exceed 5000 ha. Slopes of > 60% amounted only to 2 % of the SFRL, covering 1,690 ha, and are found mainly in Kalawana, Nivithigala, Ayagama and Palindanuwara. Frequent flood affected areas are found in 0 – 8% slope (see also sections 8 and 13). Vulnerability to landslides are “not likely” within this slope range, but narrow valleys even in the lower slopes are subjected to landslides due to geological and other factors. 3.2 Geological features The rocks of the SFRL belong to the Highland Series, consisting mainly of crystalline Precambrian rocks2 which are metamorphosed and highly deformed under high pressure and temperature conditions2 about 610-550 MYA3 . However, there are notable lithological differences between this landscape and rest of the Highland Complex, such as lack of the prominent bands of quartzite, marble and garnet sillimanite graphite schist (Khondalite) and the occurrence of wollastonite bearing calc granulites. In addition, the rocks in this region have undergone relatively low pressure (5 - 6 kbr) metamorphism compared to the rocks in the rest of the Highland series. The major rock types found here are metasedimentary rocks (such as quartzites, marbles, garnetsillimanite schists), charnockitic gneisses and allied rocks, basic rocks, migmatitic and granitic gneisses, and granites and pegmatities. Khondalite or garnet-silimanite rocks are the most striking of the metasedimentary rocks.1 The Bulutota escarpment and much of the Rakwana massif are made up largely of gently dipping, resistant charnocktic gneisses.1 Rock types in the SFRL • Charnockitic gneisses are found extensively throughout the SFRL. They are greenish grey or bluish grey in colour before exposed to the atmosphere for a lengthy period of time, and are found in large quantities at the Bulutota escarpment of the Rakwana massif.1 • Quartzites are metamorphosed sandstone and are almost entirely of re-crystallized quartz. 1 • Magnetite, the main mineral in the Sinharaja Basic Zone rocks has a relatively high magnetic intensity. • Granitic Gneisses – Generally light coloured quartz-feldspar-biotite-garnet rocks of streaky or veined appearance. 1 Source: Cooray (1967)1 2 Dissanayake, C.B., Dissanayake, D M D OK, Weerakoon, D.P. R. (2018) .Mineral Resources and Sustainable Use. Natural Resources of Sri Lanka: Conditions, Trends and Prospects., Wijeyaratne, M J S., Jayasuriya, A H M, and Wijayananda, N. P, ed. National Science Foundation, Colombo, Sri Lanka. 3 SD (2007). The National Atlas of Sri Lanka, Survey Department of Sri Lanka, Sri Lanka. © J D S Dela
3. Landscape, topography, and geology | 32 Introduction to the SFRL Gem bearing lands Considering the gem-mineralogy formations in the region of SFRL, the availability of gem minerals is very high.4 The availability of gem minerals in the SFRL are as follows (Table3.1). These areas of the Ratnapura district within the SFRL yield excellent blue sapphires, which are world famous for their high clarity, transparency and colour saturation.2 Despite the high income (foreign and local) generated through the gem industry in a large part of the SFRL, considerable socio-economic and environmental issues have been reported as a result of these activities. TABLE 3.1: Distribution of different gem mineral types in the SFRL Map sheet4 Available Gem Minerals Ratnapura Amethyst, andalusite, apatite, beryl, crysoberyl, citrine, corundum, diamond, danburite, diopside, ekanite, garnet, iolite (cordierite), kornerupine, scapolite, sillimanite, sinhalite, spinel, taaffeite, topaz, tourmaline, zircon. Aluthgama Chrysoberyl, corundum, spine, tourmaline. Rakwana Apatite, aquamarine, axinite, beryl, chrysoberyl, corundum, danburite, diopside, ekanite, enstatite, fluorite, garnet, kornerupine, spinel, tourmaline, zircon. Morawaka Aquamarine, beryl, chrysoberyl, corundum, danburite, diopside, garnet, sillimanite, sphene, spinel, tourmaline, zircon. Source: Dissanayake, et al 2000 5 4 From the map sheets of Ratnapura, Aluthgama, Rakwana and Morawaka from the Survey Department 5 Dissanayaka C.B, Chandrajith, R., & Tobschall, H J. (2000). The Geology, Mineralogy and rare element geochemistry of the Gem Deposits of Sri Lanka. Bulletin of the Geological Society of Finland. 72. Parts 1-2, pp5- 20. Figure 3.4: Spatial distribution of mineral resources in the SFRL Source: Based on Geological Survey and Mines Bureau Map.
3. Landscape, topography, and geology | 33 Introduction to the SFRL Gemstone varieties found in the SFRL Corundums: The most important gem mineral found in Sri Lanka. Includes blue, yellow, pink orange, and brown sapphires, including the high priced reddish orange pathmaraja sapphires found only in Sri Lanka; and the star-rubies and star-sapphires. Deep red rubies are rare, but hot pink rubies are relatively more common. Chrysoberyls: Occurring in yellow, brown and brownish green colours, some of which have a single ray of light known as cat’s eye, The alexandrite which is the most important variety in the Chrysoberyl group is also found in the SFRL. Spinnels: Consisting of blue, violet and a small quantity of red stones, including garnets. Zirconds: Found in abundance in the SFRL, often in yellow, green and brownish green colours. Moonstones: Found in the SFRL too, but lack the luster of those found at Meetiyagoda. Aquamarine, amethysts, citrine, tourmalines, and iolite are also found in the SFRL but they are not significant in the gem industry. The more rare Sinhalite, ekanite (radioactive), taffteite, fibrolite, andalucite, and enstatite are found in the SFRL, but they have value more as laboratory or museum pieces. Source: SD (2007) National Atlas of Sri Lanka and discussions with persons in the trade and a gemologist working in the mining industry in the SFRL River sand The SFRL is an important source of river sand mined from rivers of the SFRL which consists of >90% of quartz (SiO2) and is mined from all five major rivers flowing in it.
3. Landscape, topography, and geology | 34 Introduction to the SFRL
Soils 4 Red-Yellow Podzolic soils in hilly undulating terrain in the SFRL © J D S Dela
4. Soils | 36 Introduction to the SFRL 4. Soils 4.1 Major soil groups in the SFRL The SFRL has five major soil groups belonging to different soil series (Table 4.1). Additionally, there are several other soil types of varying importance in different parts of the landscape. This has contributed significantly to its vegetation richness, as well as the varied agricultural crops it supports. Figure 4.1 provides a detailed map of the distribution of the major soil types in the SFRL. The deeply dissected Red-Yellow Podzolic soils are the most common soil type, and is the predominant soil type in all DSDs. TABLE 4.1: The five main soil types in the SFRL Soil series name Local classification Malaboda series Red Yellow Podzolic soils Dodangoda series Red Yellow Podzolic soils with strongly mottled sub soil Weddagala series Red Yellow Podzolic soils with semi-permanent A1 horizon Pallegoda series Red Yellow Podzolic soils Mahawelatenna series Reddish Brown Earth soils Source: Based on the Soil Map of Sri Lanka by the Soil Science Society of Sri Lanka, 4.2 Features of major soil groups in the SFRL The composition and features of the major soil types found in the SFRL are described in Box 4.1. Their distribution in the 16 DSDs of the SFRL is described in Table 4.2. BOX 4.1: FEATURES OF THE MAJOR SOIL TYPES IN THE SFRL The type, texture and structure of the major soil groups in the SFRL differ as follows: • Alluvial soils: of variable drainage and texture; found in flat terrain, in valleys associated with river and stream banks, and flood plains • Bog and half bog soils: found in flat terrain; in low-lying areas, including marshes. They contain partially and fully decomposed organic material, and are ideal for paddy cultivation • Red Yellow Podsolic soils: with semi-prominent A1 horizon, occurs in hilly and rolling terrain • Red Yelllow podsolic soils: occurs in steeply dissected hilly and rolling terrain • Reddish Brown Earth & Immature Brown Loam: occurs in rolling, hilly and steep terrain • Reddish-Brown Earths and Low Humic Gley Soils: found in undulating terrain • Steep Rockland and Lithosols: found on the mountain slopes Source: SD (2007) National Atlas of Sri Lanka
4. Soils | 37 Introduction to the SFRL Figure 4.1: The spatial distribution of soil types in the SFRL
4. Soils | 38 Introduction to the SFRL TABLE 4.2. Soil type composition within the 16 DSDs of the SFRL Soil type Ayagama Elapatha Nivithigala Kalavana Kahawatta Kolonna Pelmadulla Godakawela Palindanuwa ra Agalawatta Bulathsin ghala Walallawita Neluwa Thawalama Kotapola Pitab eddara Alluvial soils of Variable Drainage and Texture; flat terrain ❖ ❖ ❖ ❖ Bog and half bog soils; Flat terrain ❖ ❖ Red Yellow Podzolic Soils with semi prominent A1 horizon; Hilly and Rolling Terrain ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ Red Yellow podsolic soils; Steeply dissected hilly and Rolling Terrain ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ ❖ Reddish Brown Earths and low Humic Gley soils; Undulating Terrain ❖ ❖ Reddish Brown Earth & Immature Brown Loam; Rolling, Hilly and Steep terrain ❖ ❖ Steep rock land & Lithosol ❖ ❖ ❖ ❖ ❖ Source: Mapa R.B. et al. (2002) Soils of the Wet Zone Sri Lanka, National Science Foundation, Colombo. Alluvial soils in paddy lands of the SFRL © J D S Dela
4. Soils | 39 Introduction to the SFRL 4.3 Laws and policies in relation to soils in the SFRL TABLE 4.3: Soil related laws and policies and their implementing agencies Laws/Policies/Plans/ Programmes Agencies Laws • The Soil Conservation Act No 25 of 1951 and its amendments • DoA • The National Environmental Act No, 47 of 1980 and its amendments • CEA • The Agrarian Development Act No 46 of 2000 • DAD Policies • The National Land Use Policy of 2007 • Ministry dealing with lands • LUPPD • The National Policy on Agriculture of 2007 • Ministry dealing with Agriculture More details of laws and policies are in Appendix 1-B “While soil is frequently referred to as the "fertile substrate", not all soils are suitable for growing crops. Ideal soils for agriculture are balanced in contributions from mineral components (sand: 0.05–2 mm, silt: 0.002–0.05 mm, clay: <0.002 mm), soil organic matter (SOM), air, and water” Source: Parikh, S. J. & James, B. R. (2012) Soil: The Foundation of Agriculture. Nature Education Knowledge 3(10):2
4. Soils | 40 Introduction to the SFRL
Hydrology 5 River in the SFRL © Chinthaka Devinda
5. Hydrology | 42 Introduction to the SFRL 5. Hydrology Water resources of the SFRL are critical for human wellbeing, agriculture and socio-economic development. The delivery of water in the required quantity and quality, is however, closely linked to the presence of healthy, functioning ecosystems to maintain the hydrological balance.1 It is generally accepted that at least 30% of river flow should remain to maintain its basic ecosystem functions and aquatic biodiversity. If rivers carry pollutants that have been added to them due to human action, this will give rise to serious health problems for humans and animals, and affect agricultural productivity and recreational use. 5.1 The rivers and their watersheds The surface waters in the SFRL are mainly from five major rivers, the Kalu, Walawe, Nilwala, Gin, and Bentota rivers (ganga) and their tributaries, which originate from the mountainous hilly terrain at the centre. The rivers flow radially across the landscape to the sea (Figure 5.1). The total basin areas of these rivers, their areas within the SFRL, and average annual discharges of these rivers that leave the SFRL are in Table 5.1. About 65% of the landscape is covered by the Kalu Ganga basin, while the Gin Ganga and Walawe Ganga basins cover about 18% and 10% of the land, respectively. The Bentota Ganga and Nilwala Ganga basins cover only a small part of the SFRL. These rivers and their perennial tributaries, which are nourished by a large number of small streams and rivulets, form a dense network of waterways in the landscape (Figure 5.2). Accordingly, the entire area is covered by a number of sub-watersheds (Table 5.1) amounting to a total area of 2141 km.2 The average annual water yield from this landscape is approximately 5243 MCM/year, which highlights the importance of the SFRL to maintain the hydrological balance of the country and to provide water for human use and socioeconomic development of the region. 1 Jones, J.A., Achterman, G.L., Augustine, L A, Creed, I.F., Ffolliott, P.F., MacDonald, L. and Wemple, B.C. (2009) Hydrologic effects of a changing forested landscape-challenges for the hydrological sciences, Hydrol. Process. 23, 2699-2704. “A river basin is defined in this document as the entire portion of land drained by a particular river and its tributaries. A basin can have many watersheds that receive rainfall within the confines of a drainage divide, which is then transferred to a marsh, stream, river, tank or groundwater. Catchment areas occur in low lying regions in which rainwater, surface runoff, and ground water from higher areas are collected into a single water body.” Kalu Ganga Basin Bentota Ganga Basin Gin Ganga Basin Nilwala Ganga Basin Walawe Ganga Basin Figure 5.1: The five river basins that occur in part within the SFRL and their stream network
5. Hydrology | 43 Introduction to the SFRL Streamflow data below are from the Hydrological Annuals published by the Department of Irrigation, Sri Lanka The available water in the landscape from rainfall, after evapotranspiration and infiltration into the soil, amounts to the surface water in rivers, streams and ponds that supports use by people, animals and plants and enables groundwater recharge (Manthrithilake, 2017).2 2 Manthrithilake, H. (2018). Water Resources of Sri Lanka. Natural Resources of Sri Lanka: Conditions, Trends and Prospects., Wijeyaratne, M.J.S., Jayasuriya, A.H.M., and Wijayananda, N.P., ed. National Science Foundation, Colombo, Sri Lanka. TABLE 5.1. Features of the five major rivers that flow within the SFRL River Total Basin Area (km2) Average Annual discharge at the most downstream gauge (MCM) Number of sub watersheds Watershed area within the SFRL (km2) Estimated Average Annual Discharge leaving the SFRL boundary (MCM) Kalu Ganga 2839 6045 (Putupaula) 13 1467 3863 Gin Ganga 915 2108 (Baddegama) 3 338 952 Nilwala Ganga 1043 504 (Pitabeddara) 3 48 65 Walawe Ganga 2424 Not gauged 4 212 226 Benthota Ganga 667 Not gauged 3 76 137 Details of sub-watersheds are in Annex 5.1 Figure 5.2: Stream network in the SFRL
5. Hydrology | 44 Introduction to the SFRL 5.2 Streamflows and trends Only three of the five rivers in the SFRL are gauged, among which the Kalu and Gin rivers have the greatest influence on the hydrology of the SFRL. The average annual streamflows for the two rivers respectively within the two gauging stations in the SFRL are 2052 MCM (Millakanda) and 1062 MCM (Thawalama). The seasonal flows of these two rivers show high variation during an annual cycle (Figure 5.3). Flows are highest during the South-West monsoon (May-June) and the second inter-monsoonal season (October-November). Hydropower generation could be high during the southwest monsoon at the Kukule Ganga Hydropower Plant and the mini hydropower plants located on the rivers and streams of the SFRL. Analysis of flow data of the Gin Ganga indicates that the minimum flow at Thawalama has varied between 0.06 m3 /s to 11.76 m3 /s during this period (1973-1998), indicating very low flows in the river during dry periods. Similarly, the Kalu Ganga (Kuda Ganga) flows indicate that the minimum flow at Millakanda has varied from 0.43 m3 /s to 27.32 m3 /s during the period from 1991 to 2017. Though the rainfall is high during certain months (e.g. May), there is no storage facility to capture these waters for later use, especially for agricultural purposes. The approximate agricultural land is about 42% of the SFRL total area and the main crops are tea, rubber, irrigated and rain-fed paddy, coconut, oil palm and perennial crops (Section 10). The paddy lands, which are about 6% of the agricultural lands are mainly rainfed. 5.3 Groundwater Groundwater is used to satisfy drinking water needs in rural areas of the SFRL, and water is tapped from springs or taken from dug wells for such needs. Water is taken from dug wells for agricultural use in certain areas, though such use is not very high. However, these water uses have not been quantified or properly monitored in the past. “Streamflows denote the amount of water flowing through a river or stream over a fixed period of time.” “Groundwater is derived mainly from rainfall seepage and recharge from surface water bodies such as rivers and streams in the landscape” Figure 5.3: Monthly flows for Kalu Ganga and Gin Ganga Source: Hydrological Annuals published by the Department of Irrigation, Sri Lanka. Average Monthly Flow (MCM)
5. Hydrology | 45 Introduction to the SFRL 5.4 Overall assessment of surface and groundwater availability Average annual rainfall towards the southwestern part of the SFRL is more than 4500 mm while the eastern part receives a comparatively less rainfall of about 2500 mm in a year. The high rainfall in the southwestern part of the island is partly due to the topography of the island. The central hills that rise above 2000 m intercept the moisture-laden monsoon winds, especially on steeper flanks, bringing high rainfall to the southwestern part of the island. Although there are no large storage reservoirs to support irrigation in the SFRL, there are many anicut type irrigation schemes within the landscape to distribute water in space, but not in time. The monthly rainfalls recorded at the gauging stations indicate that rainfall is received throughout the year, with very high rainfall during the southwest monsoon and second inter-monsoon periods. 5.5 Forests and the hydrological cycle Figure 5.4 shows the importance of forests in the SFRL determined by the National Conservation Review (NCR) of forests in the country, carried out in the mid 1990s. The importance of the Sinharaja NHWA with 337 streams is highlighted, followed by Dellawa, Diyadawa and Handapanella with >70 streams each. Morapitiya-Runakanda, Kudumeeriya, and Kalugala reserves had >50 streams originating within their boundaries respectively, and even miniscule Handuwelkanda (378 ha), which appears very fragmented now , had 3 streams originating from it. Not only do these streams provide water for people (section 7), they provide habitats for a large number of aquatic wet zone species, many of which are endemic and/or threatened with extinction. These species would be deprived of their dwindling habitats if the forested catchments of the SFRL are destroyed or degraded further. Overall, the NCR identified 85 individual forests of prime importance for the conservation of soil and flood control in the country, of which 28 are within the SFRL (Figure 6.11, section 6). In addition to the forest areas, the SFRL consists of diverse plantation and other crops, homesteads, built-up areas, etc. Some of these land uses may contribute to the pollution of water in the SFRL. Figure 5.4: Streams originating from forests of the SFRL surveyed during the NCR Source of map data: IUCN/WCMC/FAO 1997a
5. Hydrology | 46 Introduction to the SFRL BOX 5.1 THE ROLE OF FORESTS IN CREATING HYDROLOGICAL BALANCE AND REDUCING SOIL EROSION Of all the ecological services of forests, providing a sustainable water supply and streamflow is considered the most important (Jones, et al, 2009). The heavy and high intensity rainfall in the tropics is often composed of raindrops of 3-5 mm diameter, making raindrop impact critical on highly erosive or exposed soils, as it causes soil compaction and surface sealing . This leads to reduced water infiltration, and increased surface run-off, resulting in brown, silt-laden rivers. The uninterrupted forest canopy in rainforests results in rainfall interception, with reduction of the force of raindrops by the tree crowns; and with water trickling down trees also taking longer to reach the soil. The quantity of water reaching the ground is also reduced as some moisture evaporates from the leaf surfaces, and transpiration helps to keep the water cycle moving. Forest leaf litter retains moisture, protects soil from direct raindrop impact, and the mat of roots near the surface binds the soil together. This also provides mechanical support on steep slopes contributing to slope strength and preventing landslides. Rainforests: help moderate rainfall intensity, virtually eliminate raindrop erosion, and help windspeed reduction. They also provide ground cover in water catchment areas to reduce sediment loading of streams and rivers that flow from them. Source: Evans (1986),3 (Jones, et al, 2009). Streams in the southern part of the Sinharaja forest drain into the Maha dola, which eventually join the Gin Ganga, which directly originates from the southern section of the Sinharaja forest, and flows in a westerly direction along its southern border, deviating at Happitiya. Watercourses on the forest’s northern boundary include the Napola dola, Koskulana Ganga and Kudawa Ganga, which are tributaries of the Kalu Ganga. Additionally, headwaters of tributaries of the Nilwala Ganga, Walawe Ganga and Bentota Ganga flow from forests that are part of the Sinharaja Rainforest Complex. 5.6 Water sources and demand There is sufficient water for most parts of the SFRL. However, some DSDs, reported to have less water have drinking water supply schemes. For example, the Embilipitiya Water Supply Scheme (capacity: 18,000 m3 /day); Kolonna Water Supply Scheme (capacity: 7,000 m3 /day); and the Godakawela Water Supply Scheme (capacity: 4,500 m3 /day) provide drinking water to these relatively dry areas. However, irrigation water for agriculture is often insufficient in these areas. Drinking water There are many community based small water supply schemes within the SFRL that obtain surface water. Some of these are managed by either a local governing authority or a community based organization. However, some forest springs are exploited heavily for domestic water use by individuals without any controls, leading to severe water wastage, habitat loss for aquatic organisms due to poor flows during the dry season, and other environmental impacts (see Part II ST 10 SO 10.2). At present, existing district wise water supply coverage by the National Water Supply and Drainage Board, through water supply schemes is 48.7% in the Kalutara district, 17.3% in the Ratnapura District, 35.5% in the Galle district, and 41.3% in the Matara district. A few new drinking water supply projects have been proposed to enhance water availability in the Ratnapura district within the SFRL area (e.g. Nivithigala, Kalawana and Doloswala schemes). Table 5.2 shows some drinking water supply schemes in the Ratnapura district that fall within the SFRL with their sources and capacities. However, these schemes mostly cover the requirements of urban areas while rural areas depend largely on community based water supply schemes, generally from forest springs, and individual dug wells. 3 Evans. J. (1986). Plantation Forestry in the Tropics. Oxford University Press. New York.
5. Hydrology | 47 Introduction to the SFRL Major hydropower plants Kukule Ganga Hydropower Scheme The 80 MW Kukule Ganga hydropower plant is located on the Kuda Ganga (i.e. a tributary of the Kalu Ganga). The Kuda Ganga catchment up to the Kukule Ganga dam is about 312 km2 . The Kukule Ganga Hydropower plant was commissioned in 2003. Mini-hydropower schemes Figure 5.5 presents the location of 26 mini-hydropower plants in and immediately outside the SFRL. Of these, 17 are within the Kalu Ganga basin. A further 2, 6 and 1 plants occur in the Walawe, Gin, and Nilwala river basins, respectively. The names and location details of these mini-hydropower plants are in Annex 5.2. All mini-hydropower plants are connected to the national grid and serve a major development function. However, some impacts from minihydropower plants that have not adhered to guidelines issued remain an environmental concern. Water Supply Scheme (Name) DS Division Water Source Treatment Plant Production Capacity (m3 /day) Godakawela Godakawela Rakwana Ganga 4,500 Kahawatta - Pelmadulla Godakawela, Kahawatta, Pelmadulla Way Ganga and Kirindi Ela 10,500 Kolonna Kolonna, Embilipitiya Eraporuwa Ganga 7,000 Nivithigala Elapatha, Nivithigala Watapotha Ela 1,800 Kiriella Kiriella Bore hole 600 TABLE 5.2. Water supply schemes in the Ratnapura district Figure 5.5: Mini-hydropower Schemes in the SFRL Kukuleganga dam
5. Hydrology | 48 Introduction to the SFRL Irrigation schemes Except for the Kukule Ganga Reservoir, rivers and their networks are the most important surface water resources in the SFRL. Nevertheless, there are six irrigation schemes within the SFRL (Figure 5.6). The Department of Agrarian Development (DAD) has identified many minor irrigation schemes in eight DSDs of the SFRL. Most of these irrigation schemes are expected to be rehabilitated to improve their performances (Annex 5.3). These are mostly anicut schemes without any storage, so that they will not contribute to distribution of water in time. 5.7 Factors impacting water quality and availability Water chemistry Major watershed components, hydrology, soil types, geology, vegetation, chemical weathering processes, and exchange of elements in soils due to natural and anthropogenic action contribute to the chemical composition of water. However, systematic water quality data collection programmes have not been carried out in the SFRL to identify impacts of recent land use changes on water quality. Impact of development The proposed Gin-Nilwala Diversion Project Gin-Nilwala Diversion Project (GNDP) is a multi-sector development project that is planned to divert excess water to the southeast dry zone via a reservoir group in the upper reaches of the Gin-Nilwala river basin (Figure 5.7). This is expected to provide drinking water, meet the irrigation deficit, improve quality of existing irrigation systems, introduce commercial agriculture development, and provide the industrial water requirement to the Greater Hambantota Development Area. The proposed dams and water diversion are expected to reduce flood impacts. However, the structural and other impacts on the SFRL region is incompletely known (see also Part II ST 9). The most upstream reservoir of this proposed project at Figure 5.6: Major and minor irrigation schemes within and close to the SFRL boundary Figure 5.7: The map of the proposed Gin-Nilwala Diversion Project
5. Hydrology | 49 Introduction to the SFRL Madugeta is estimated to inundate about 5 ha of the Sinharaja forest, and about 4 ha of small patches of forests unconnected to the Sinharaja Forest. Further about 20 ha of the Dellawa forest (Part of the Sinharaja Biosphere Reserve) will also get inundated by this reservoir. In view of these issues these activities have been halted at present, as there is a real danger of losing the Word Heritage Site (WHS) and SBR if these projects impact them. Dams of this magnitude are not possible within a WHS or the buffer zone of a UNESCO Biosphere Reserve. The proposed Kalu Ganga flood mitigation project A project is proposed to construct three dry dams to mitigate floods at Ratnapura. One of the dams is at Malwala (former Karawita), while the other two are at Dela. There is also a plan to build a salinity barrier and a structure to develop the river mouth to release flood flows downstream for mitigating floods in the lower basin of the Kalu Ganga. The proposed Transbasin Diversion Project from Kalu Ganga basin to Walawe Basin A project is being explored to divert water from the Kalu Ganga basin to Walawe Ganga basin using three reservoirs built across Kukule Ganga, Nirieli Ganga and Rakwana Ganga. The recipient is a branch of Kuda Oya, which will carry water to the Walawe Ganga. Propensity of rivers for flooding In the Kalu Ganga basin area the SFRL, the Palindanuwara and Bulathsin fflhala DSDs in the Kalutara district and the Ayagama, Nivithigala, Elapatha, Ratnapura and Pelmadulla DSDs in the Ratnapura district, are affected by floods. Many flood protection measures have been proposed to minimize flood inundation in these areas as mentioned previously. A few locations within the SFRL in the Gin Ganga basin are affected by floods. These areas are in the Thawalama and Neluwa DSDs in the Galle district and in the Kotapola DSD in the Matara district. However, these inundations are mostly limited to low-lying areas along the river. The inundation areas in the Nilwala Ganga basin within the SFRL occur in Kotapola DSD division. Assessment of the impacts of watershed development initiatives Many new development projects have been proposed within the SFRL as given above. Most of these have been proposed for mitigating flood inundation. Additionally, there are existing hydro-power schemes, irrigation schemes, etc., within the SFRL. Impacts of these presently available schemes and proposed projects need to be investigated thoroughly to identify their negative impacts on the environment and water resources. Any proposed project needs to be evaluated through relevant impact assessments to minimize impacts that will damage the biodiversity and ecosystem integrity of the landscape. 5.8 Laws and policies in relation to hydrology in the SFRL Laws/Policies/Plans/Programmes Implementing agencies Laws • Irrigation Ordinance No 32 of 1946 and its amendments Dept. of Irrigation • National Water Supply and Drainage Board Act No.12 of 1972 and its amendments National Water Supply and Drainage Board • Water Resources Board Act No 29 of 1964 and its amendments Water Resources Board • Flood Protection Ordinance No 2 of 1924 Dept. of Irrigation • The Electricity Act No. 19 of 1950 Ceylon Electricity Board Policies • The National Environmental Policy of 2003 MoE, CEA • National Watershed Management Policy of 2004. Dept. of Irrigation • The National Wetland Policy and Strategy of 2006 MoE, CEA • Standards for effluent discharge by gazette notification No 559/16 of February 2nd 1990 CEA • The National Land Use Policy of 2009 Min of Land, Land Comm. Gen. Dept TABLE 5.3: Water related laws and policies and implementing agencies
5. Hydrology | 50 Introduction to the SFRL
Forests 6 © Wildlife Conservation Society- Galle
6. Forests | 52 Introduction to the SFRL 6. Forests 6.1 Overview of forests in the SFRL The forests of the SFRL cover 62,049 ha, amounting to 29% of its land area. These forests are the very heartland of Sri Lanka’s famed biodiversity. Thus, the SFRL contains much of the most valued rainforests in the country, with characteristically rich biodiversity at the ecosystem, species and genetic levels. These forests are also unique due to their exceptional endemism,2,3,5 making them of national and international significance, as evinced by the presence of the Sinharaja Forest Reserve World Heritage Site and the Sinharaja Biosphere Reserve. There are over 190 forests of varying size, type and category, identified by name within the SFRL (Figure 6.1). These include three forest complexes recognized by the National Conservation Review (NCR) as important for conservation of the nation’s indigenous floral diversity, and two considered important to conserve indigenous faunal diversity.2,3 They are 14 forests of the Sinharaja Complex, seven forests of the Walankanda Complex, and two forests of the Haycock complex.3 Many of these are included in the forest reserves comprising the Sinharaja Rainforest Complex which was gazetted in 2019. Forests of the SFRL (Figure 6.2) have been classified as tropical evergreen forest, comprised mostly of lowland rainforest that transition into sub-montane tropical forests and grasslands towards its eastern end,6 and a small area of moist monsoon forest in the Kolonna DSD. Grasslands are clearly seen in Handapanella and the contiguous Beragala and Kabaragala forests7 . Despite their 1 Premakantha, K T, Chandani R P D S., Kingsly, S A D, Dias, H U, and Kekulandara, N S B (2021). Forest cover assessment in Sri Lanka using high resolution satellite images, Sri Lanka Forester, Vol 40. pp 1-16. 2 IUCN/WCMC/FAO (1997a). Volume 1. Designing an optimum protected areas system for Sri Lanka’s natural forests (I). IUCN, Sri Lanka (unpubl.). 3 IUCN/WCMC/FAO (1997b). Volume 2. Designing an optimum protected areas system for Sri Lanka’s natural forests (I). IUCN, Sri Lanka (unpubl.). 4 MoF&E (1999). Biodiversity Conservation in Sri Lanka: a Framework for Action. 5 Gunatilleke, CVS and Gunatilleke, IAUN (1985). Phytosociology of Sinharaja-A contribution to rainforest conservation in Sri Lanka, Biological Conservation, 31. 21-40. 6 Jayasuriya, A H M, Kitchener, D., Biradar, C M (2006). Portfolio of Strategic Conservation Sites/Protected Area Gap Analysis in Sri Lanka, MoENR (unpublished). 7 The NCR does not mention the latter two forests which were possibly a part of Handapanella when surveyed by the NCR. Importance of Sri Lanka’s wet zone forests Sri Lanka’s natural forest cover of 1,912,970 ha amounts to 29% of the land area, including open and sparse forests, mangroves, and savanna.1 During the 2015 forest cover map preparation, the following forest types were identified: montane forest (40,162 ha), submontane forest (28,349 ha), lowland rain forest (124,389 ha), moist monsoon forest (120,300 ha), dry monsoon forest (1,122,375 ha), mangroves (19,758 ha), open and sparse forests (389,562 ha), and savanna (68,075 ha). Of these, the forests of Sri Lanka’s wet south-west and south-central quarter are home to the country’s richest biodiversity as reported by the National Conservation Review (NCR) of natural forests carried out by the Forest Department in the 1990s.2,3 Wet zone forests harbour over 90% of the country's woody endemic flora, and about 75% of the endemic fauna,4 all the endemic genera, and most of the relict species; with levels of endemism in Wet Zone forests ranging from 37-64% for woody plants and 14-52% for animals.4 Further, many of the endemics, among both fauna and flora are highly localized,4 often resulting in point endemism (see section 7), highlighting the importance of conserving these forests. The Wet Zone forests are also the most important forests island-wide in terms of soil and water conservation.2,3 They play a vital role in maintaining hydrological cycles and providing freshwater for agricultural and domestic use, and for producing hydroelectricity. Most Wet Zone forests (even the degraded forest fragments) have a high watershed value, as rural villagers near these forests depend heavily on them to obtain freshwater for their daily domestic requirements – either directly, or for recharge of ground water from wells. “The concept of contiguous forest units provides an excellent proxy for the improvement of the viability of small forest sites if it can be adopted into management of the protected areas, at least in the wet zone where the biodiversity is considerably threatened.” (Source: Jayasuriya, et.al, 2006)6
6. Forests | 53 Introduction to the SFRL intrinsic value in terms of Sri Lanka’s wild biodiversity, many forests within the SFRL have been selectively logged during the 1970s for timber, resulting in the Sinharaja NHWA being the only sizable lowland rainforest that is relatively undisturbed in the country.8 Nonetheless, many forests in the SFRL were found to support a rich biota during the National Conservation Review in the mid 1990s. It is of concern that a large number of these forests now exist as small forest fragments in the SFRL, isolated and surrounded by human settlements and agriculture (Figure 1.4, section 1). This map was prepared using shape files of the 2015 forest cover map provided by the Forest Department, and re-checked during preparation of the SFR-LMP with FD field officers in the range forest offices of the SFRL to ascertain accurate presentation of each forest in the map at a fine scale. The map was revised accordingly during meetings with the GIS division of the FD via an initiative of ESCAMP with the participation of the relevant members of the SFR-LMP preparation team. Some areas have been marked for field checking; but the maps used in this document provide the most accurate depiction of forest area, type, category, ownership and connectivity at present. All individual forests have been named according to NCR usage, and according to current usage for those that were not surveyed then. However, only forests that either: (a) have data on species, hydrology, or soil erosion potential from the NCR; (b) are part of the forest complexes prioritized for conservation by the NCR; (c) are gazetted as a NHWA, Conservation Forest or Forest Reserve; (d) are part of the SBR Core Zone or Buffer Zone, or (e) were identified as important by ESCAMP are named in this map to preserve clarity. The list of all forests in the SFRL identified by name is in Appendix 6-A. 8 Gunatilleke, CVS and Gunatilleke, I A U N (1983). Effects of mechanized logging in Sinharaja, The Sri Lanka Forester, Vol. XVI. Nos 1&2, pp 19-24. Figure 6.1: Forests within the Sinharaja Forest Range Landscape (SFRL) with forest complexes identified by the NCR Source: Forest map prepared for the SFR-LMP based on FD 2015 map data revised in 2020&2021
6. Forests | 54 Introduction to the SFRL 6.2 Floristic features The SFRL occurs within Floristic Region C2 termed Sinharaja and Ratnapura, with Kalugala and the Haycock complexes falling within Floristic Region C3 termed Southern Lowland Hills Floristic Zone.9 The forests in region C2 are floristically unique, and considered the most species-rich among the Sri Lankan forests. 10, The composition of forest types in C3 are similar to those in C2, but the area receives more rainfall than C2. The floristic composition of forest types in the SFRL are described in detail below. 9 MoMD&E (2019) Biodiversity Profile - Sri Lanka, Sixth National Report to the Convention on Biological Diversity, Biodiversity Secretariat, Ministry of Mahaweli Development and Environment, Sri Lanka. pp.200 10 Ashton, P S and Gunatilleke C V S (1987). New light on the plant geography of Ceylon, I: Historical plant geography. J. of Biogeogr.,14: 249-285. Figure 6.3: Floristic Regions for the SFRL Source: MoMD&E, 20199 Figure 6.2: Forest types in the Sinharaja Forest Range Landscape (SFRL) Source: Forest map prepared for the SFR-LMP based on FD 2015 map data as revised in 2020 & 2021
6. Forests | 55 Introduction to the SFRL BOX 6.1: DEFINITION OF FOREST Under the Forest Ordinance No. 16 of 1907, a forest is defined as all land at the disposal of the state, including all forest, wastelands and chena, which are uncultivated or unoccupied, and all lands resumed under the Land Resumption Ordinance, Waste Lands Ordinance, and Land Settlement Ordinance. By gazette notification, the Minister in charge of the subject can declare all or any of such land as “reserved forests”. The Minister can also declare “any portion of forest” as “village forests,” on the legal basis for village forests in the Ordinance. More recently, forests have been defined for purposes of Carbon holding assessments as land with tree crown cover of more than 10% and an area of more than 0.5 ha with trees able to reach a minimum height of 5m at maturity. Source: SLURP, 201711 Lowland Wet Evergreen Forests (LWEF) These are the widespread forests of the wet lowlands in the south-west sector of Sri Lanka, occurring up to an elevation of 900 m. These areas have a mean annual temperature of about 280C, a mean annual rainfall around 2,300-5,000 mm throughout the year, and a humidity of 75-85%, exceeding 90% during seasons of high rainfall. The wet and warm tropical climate has enabled development of an extremely complex ecosystem with distinct strata. A main feature of these forests are the tall trees with dense canopies that rise to about 30m and display characteristic cauliflower shaped crowns. Emergents of >45m rise above the canopy.12 A broad sub-canopy of 15-30 m, a sparse shrub layer (consisting mostly tree saplings), and a scanty herbaceous ground flora are also part of the forest profile. Lianas are common, and epiphytes, mainly ferns, orchids, lichens, fungi and bryophytes, are abundant. Epiphyllous mosses and liverworts add diversity to the vegetation. Examples of main constituents of these forests are: Emergents – Shorea dyeri, Shorea stipularis, Shorea congestiflora and Shorea affinis. Canopy – Shorea trapezifolia, Dipterocarpus zeylanicus, Dipoterocarpus hispidus, Palaquium petiolare and Mesua pulchella. High sub-canopy –Cullenia ceylanica, Cullenia rosayroana, Bhesa ceylanica, Calophyllum bracteatum, Calophyllum thwaitesii, Mastixia tetrandra, Syzygium firmum, Chaetocarpus castanocarpus, Hydnocarpus octandrus, Cryptocarya wightiana, Myristica dactyloides and Anisophyllea cinnamomoides. Low sub-canopy – Dillenia triquetra, Garcinia hermonii, Xylopia championii, Cinnamomum dubium, Memecylon rostratum, Allophylus zeylanicus and Schumacheria castaneifolia High shrub / treelet – Gyrinops walla, Aporosa lanceolata, Gaertnera rosea, Gaertnera vaginans, Microtropis wallichiana, Litsea longifolia, and Ochlandra stridula Low shrub – Lijndenia capitellata, Psychotria dubia var. affinis, Psychotria nigra var. nigra, Thottea siliquosa, Lasianthus oliganthus, Dracaena thwaitesii, and. Dichapetalum gelonioides Lianas – Connarus championii, Dalbergia rostrata, Salacia reticulata, Salacia diandra, Kadsura heteroclita and Calamus zeylanicus Mid-elevational Evergreen Forest/sub-montane forests (MEEF) These forests are transitional between Lowland Wet Evergreen Forests and Montane Evergreen Forests, and occur between 900-1400m. The mean annual temperature here is 18 – 230 C, and the mean annual rainfall ranges from 1750 – 2600 mm. The forest profile has less strata than Lowland Wet Evergreen forests. The canopy generally reaches up to 15-20 m, with no emergents, but in dipterocarp-dominated stands some Doona species rise up to about 30 m. The sub-canopy and the shrub layers in these forests are less distinct than in LWEF; but can be recognized in undisturbed forests. Examples of the main constituents in these forests are: Emergents - Shorea gardneri, Shorea zeylanica. Canopy - Elaeocarpus glandulifer, Myristica dactyloides, Cryptocarya wightiana, Palaquium hinmolpedda, Paracroton pendulus subsp. Zeylanicus, Syzygium gardneri, Semecarpus nigroviridis, Calophyllum acidus, Aglaia apiocarpa, Dysoxylum championii and Cullenia ceylanica Sub-canopy - Nothopegia beddomei, Hortonia floribunda, Acronychia pedunculata, Celtis timorensis, and Melicope lunu-ankenda Shrubs - Agrostistachys borneensis, Eurya spp., Ilex denticula, Maesa indica, Psychotria nigra, and Saprosma foetens Lianas and climbers - Freycinetia walkeri, Pothos remotiflorus, Elaeagnus latifolia, and Asparagus falcatus Source: Portfolio of Strategic Conservation Sites/Protected Area Gap Analysis in Sri Lanka, 20066, (Species nomenclature was updated according to the National Red List 2020 for Flora, names not in the Red List were deleted) The local and regional meso-climatic variation in altitude and temperature; geographical factors such as relief, gradient, soil depth, and distribution of minerals has resulted in a variety of niches in ridges, slopes and valley bottoms. This has influenced the assemblage of species in these forests into distinct communities. Pemadasa (1995, 11 SLURP (2017). National REDD+ Investment Framework and Action Plan (NRIFAP), Sri Lanka UN- REDD Programme. 12 Some variation exists: on exposed ridges and hill tops, canopy height may be about 2-3 m (see Gunatilleke and Gunatilleke (1985).5
6. Forests | 56 Introduction to the SFRL cited in Jayasuriya, et al., 2006) recognized Dipterocarpus communities in valley bottoms, Mesua – Doona community on hill slopes and Vitex – Wormia – Chaetocarpus – Anisophyllea community on eroded hill slopes - especially on lateritic soils.6 The NCR and Protected Area Gap Analysis in Sri Lanka The NCR is regarded as the most fitting precursor and the foundation of the more recent GAP Analysis which extends the goals of the former. The NCR was carried out between 1991 and 1996 by the FD, with technical assistance from IUCN and WCMC, resulting in a systematic assessment of 204 natural forests that were ≥ 200 ha in the island, except in the north and east which could not be accessed at the time. Assessments were restricted to woody plants, vertebrates, butterflies and molluscs, as well as the hydrology of these forests.4 Much work has also been done through the Protected Area Gap Analysis carried out by the then Ministry of Natural Resources and Environment which culminated in a report in 2006. 6 The GAP analysis sought to assess the representation of Sri Lanka’s existing designated area network at the ecosystem level, and to consider its wilderness quality and viability. This provided a base for identifying a portfolio of strategic conservation sites (i.e. a collection of selected conservation planning units) for Sri Lanka which better represent biological diversity and ecological systems. It also identifies the importance of including the eastern Sinharaja area into the Protected Area Network.6 Work done by the Protected Area GAP Analysis in Sri Lanka6 shows that forests of the SFRL qualify as medium-high wilderness and medium-low wilderness (Figure 6.4), 13 probably due to the proximity of the forests to anthropogenic activity. However, viability status of these forests are rated as very good (Figure 6.5). Studies have revealed the heterogeneity of the Sinharaja forest due to clear micro-climatic differences within a relatively small spatial area,4 resulting in different areas having their own floristic features, and with no single area of the forest representing its entirety.5 The distinct species differences among the flora at different sites is particularly obvious in the canopy and sub-canopy.14 Thus, forests of the SFRL show considerable variation in species composition.3 Analysis of the NCR data for woody plants in 29 forests surveyed in the SFRL, showed the presence of Dipterocarpus zeylanicus, found mainly in valleys, in only 17 forests (58.6%); namely: Rammalakanda, Walankanda, Nahitimukalana and Delwala, Kiribathgala, Waratalgoda, Kudumeeriya, Sinharaja NHWA, Morapitiya-Runakanda, Thibboruwakota, Dellawa, Diyadawa, Kalubowitiyana, Kalugala, Paragala, Neluketiya Mukalana, and Delmalla-Yatagampitiya. Dipterocarpus hispidus which generally occurs at higher elevations was found only in 10 forests (34.4%), namely: Rammalakanda,* Wewalkandura, Delwala* and Nahitimukalana* (in the Walankanda Complex); Kudumeeriya* Morapitiya-Runakanda,* Thibboruwakota,* Sinharaja NHWA*, Delgoda and Kalubowitiyana.*15 Rubiaceae was the most species rich plant family in the SFRL (8%) of all species, followed by Dipterocarpaceae (6%), Melastomataceae (5 %) and Myrtaceae (5%). Dipterocarpaceae, a dominant family in lowland rainforests5 with >90% endemism among the species, were from 37 of species in the forests sampled in the SFRL. 13 This is based on the Wilderness Index which takes into account remoteness from settlements, (i.e. permanently occupied buildings, cleared agricultural land and plantation forests); remoteness from access (e.g. roads, railways, aircraft runways) and aesthetic naturalness (the degree to which the landscape is free from the presence of permanent structures of modern technological society – all manmade structures, ruins, quarries). (See Jayasuriya et al, 2006)6 14 De Zoysa, N.D. and Raheem, R. (1990). Sinharaja: A Rain Forest in Sri Lanka. March for Conservation. Colombo. 15 Forests in which both Dipterocarpus zeylanicus and D. hispidus were found are denoted by * Figure 6.4: Wilderness Index values Source: MoENR, 20066
6. Forests | 57 Introduction to the SFRL All these forests, including the Sinharaja NHWA, had Myristica dactyloides (Myristicaceae), while Semecarpus gardneri (Anacardiaceae), Caryota urens (Arecaceae), Garcinia quaesita (Clusiaceae), Dillenia triquetra (Dilleniaceae), Diospyros insignis (Ebenaceae), Cinnamomum dubium (Lauraceae), Cryptocarya wightiana (Lauraceae), Psychotria nigra (Rubiaceae), Allophylus zeylanicus (Sapindaceae) and Gyrinops walla (Thymelaeaceae) occurred in 97% of forests (N=28).16 (note: endemics are in bold). Interestingly, 154 woody plant species occurred in only one forest each, within 21 out of 29 forests surveyed for woody plants during the NCR.17 This is congruent with the fact that Sri Lanka’s wet zone forests are known for point endemism, some species even being restricted to a single location within a forest. Forests of this region also show marked genetic differences within a single species even in adjacent forests that are isolated from each other.18 These unique features of forests in the SFRL makes conservation of only representative forests or selected areas of existing forests very inadequate, and highlight the importance of conserving all forests in this landscape in its entirety. This is particularly relevant because it is estimated that breeding stocks of rare species should comprise at least 200 individuals for a minimum population size to conserve the community type, which in turn needs a minimum of 2000 ha of mixed - Dipterocarp forest.19 This also highlights the issue of forest fragmentation and isolation in the SFRL that has to be resolved (More details of species richness among the flora are in section 7: Biodiversity and Ecosystem Services). 6.3 Forest category, type and ownership Figure 6.6a shows the proportionate composition of forest categories present in the SFRL.20 Dense Forest covers 54,765 ha, and amounts for 88% of all forest land in the SFRL. Open and sparse forests comprise 4,243 ha (7%), while plantation forests comprise 1,876 ha (3%). The most common forest type in the landscape is lowland rainforest (50,935 ha) which comprises 85% of natural forest in the landscape. There are 4,542 ha of sub-montane forest in the Kolonna and Kalawana DSDs, and a very small area (364 ha) of moist monsoon forest in the Kolonna DSD (Figure 6.2). Of the 62,049 ha of forest in the SFRL, 54,372 ha (88 %) are managed by the Forest Department, while the balance forests are under the LRC (being acquired by the FD), other private ownership, or other state agencies (Figure 6.6a). These forests include crop plantation company owned natural forests (1,166 ha). 16 Endemics are in bold type. 17 Namely: Sinharaja, Neluketiya Mukalana, Handapanella, Kalubowitiyana, Gorangala, Kiribathgala, Kalugala, Thibboruwakota/Horakanthelya, Ayagama (now Mawarakanda), Morapitiya-Runakanda, Walankanda, Waratalgoda kitulatura, Gongala, Diyadawa, Nahitimukalana, Rammalakanda, Silverkanda, Massimbula, Auwegalakanda, Dellawa, and Kudumeeriya. 18 Prof. IAUN Gunatilleke, pers. comm 2003. 19 Gunatilleke C V S and Ashton, P S (1987). New light on the plant geography of Ceylon, II: The ecological biogeography of the lowland endemic tree flora14:. J. Biogeogr., 14. 295-327. 20 Forest categories are defined in the FD forest shape files as dense forest, open and sparse forests, shrubs, grasslands, and plantation forests. Figure 6.5: State of viability of forests in the SFRL Source: MoENR, 20066
6. Forests | 58 Introduction to the SFRL Of the forest land currently under the FD in the SFRL: 49,220 ha consists of dense natural forest, while the balance comprises plantation forest (1,723 ha) and open and sparse forest (3,429 ha). In addition, the SFRL has 818 ha of shrubs, 66 ha of grasslands and 101 ha termed other non-forest lands (this totals 986 ha of non-forest lands). Of this, the FD owns some grasslands, shrubs and other non-forest lands collectively amounting to 594 ha. There are a further 392 ha of grasslands and shrubs under LRC, private and various other sources (Figure 6.6b). These areas can be explored for restoration through enrichment, reforestation or afforestation. Much of the grasslands under the FD are invaded by the fern Dicranopteris linearis (kekilla) and grasses (e.g. Imperata cylindrica or illuk), making restoration of some heavily degraded areas a difficult process. The LRC owns around 5,101 of forests in the SFRL in total (including forest plantations), and some are in the process of being acquired by the FD, although the formalities of such a take-over is proving to be a very protracted process. Some biologically valuable forests owned by the LRC, mainly in the Kalawana, Embilipitiya, Rakwana and Deniyaya Forest Ranges, have already been boundary DF Dense forest O&S Open and Sparse FP Forest Plantation SHRB Shrub GRL Grassland ONF Other Non-Forest FD Forest Department owned OS Other State Forest LRC Ownership Land Reform Commission PVT Other privately owned PLC-F Forests owned by Plantation Companies Figure 6.6a: Vegetation category and ownership of forests within the SFRL * DF -FD DF-LRC DF-OSF DF-PVT DF-U O&S-FD O&S-LRC O&S- OSF O&S-PVTO&S-U FP-FD FP-LRC FP-OSF FP-PVT FP-U PLC-F DF -FD DF-LRC DF-OSF DF-PVT DF-U O&S-FD O&S-LRC O&S- OS O&S-PVT O&S-U FP-FD FP-LRC SHRB-FD SHRB-LRC SHRB-OS SHRB-PVT SHRB-U GRL-FD GRL-LRC ONF-FD SHRB-FD SHRB-LRC SHRB-OS SHRB-PVT SHRB-U GRL-FD GRL-LRC ONF-FD Figure 6.6b: The shrub, grassland, and non-forest lands available for possible restoration within the SFRL U Unidentified
6. Forests | 59 Introduction to the SFRL marked, and are monitored by the FD to prevent encroachment and tree felling. However, as the FD has no stringent powers in these lands yet, illegal activities cannot be fully controlled, and these forests remain very vulnerable to further degradation. However, there are financial and other issues that preclude early acquisition. Examples of large crop plantations with forest land are Ensalwatte, Kurulugala and Doraliya Watta (Mathurata Plantations); Mannikawatte (tea) Hemagiriya Watte, Punchi Kurulugala Watte, [Deniyaya Forest Range] and Aigburth [Embilipitiya Forest Range]. Many of the managers/owners of the plantations are willing to conserve these forests for environmental reasons and for ecotourism development. For instance, Aigburth Estate felt that the wind current from the Sinharaja forest contributed to the special fragrance of their high-priced dwarf tea named the “Aigburth treasure”. 21 Some plantations seek to continue on-going cardamom harvesting. 6.4 Forest conservation categories Figure 6.7 shows the conservation categories of forests within the SFRL. At the centre lies the Sinharaja National Heritage Wilderness Area (NHWA) which is also the Core Zone (11,427.9 ha) of the Sinharaja Biosphere Reserve (SBR). The Sinharaja Forest Reserve World Heritage Site lies within the Sinharaja NHWA. 21 Discussions with plantation sector during preparation of the SFR-LMP. Figure 6.7: Forest conservation categories within the SFRL Source: Forest map based on FD 2015 map data revised in 2020/21 during preparation of the SFR-LMP
6. Forests | 60 Introduction to the SFRL The Forestry Sector Master Plan of Sri Lanka predicted the country’s forest cover would dwindle to around 22% by 2020,22 based on the rate of deforestation of 42,200 ha/year between 1956 to 1983, and 54,000 ha per year from then on to about 1999.23 This led to several important changes in national forest policy and forest management, leading to a decline of forest cover loss to 8088 ha/year between 2000-2010.11 There has also been an appreciable growth of Protected Areas in the country since the 1990s. They currently include 26 National Parks; 7 Nature Reserves, 3 Strict Nature Reserves, 65 Sanctuaries and one elephant corridor managed by the Department of Wildlife conservation.24 The FD manages one National Heritage Wilderness Area, 128 Conservation Forests, and 808 Forest Reserves (FD data). The government policy at present is to increase the forest cover to 30% of the island by 2030.25 However, major drivers of forest change remain unabated. In 2017, the most damaging have been unplanned infrastructure development, private agriculture, localized small social activities driven by demand for timber and wood products, household needs, and construction requirements.11 Figure 6.8 shows that of the 62,049 ha of forests in the SFRL (including dense forest, plantation forest, open and sparse forest), 18% comprises the Sinharaja National Heritage Wilderness Area/Core Zone of the SBR (11,427 ha) gazetted under the NHWA Act No. 3 of 1988. A further 5,562 ha and 24,808 ha consists of Conservation Forests and Forest Reserves gazetted respectively under the Forest Ordinance of 1907 and its amendments. These gazetted areas make up 67 % of all forest land in the SFRL. However, some Forest Reserves have privately held lands in them (e.g. Kalugala forest) based on permits (e.g. Jayabhoomi, Swarnabhoomi, or LDO permits) from the District Secretary/Land Commissioner, and more rarely by gazette notification (see section 1). A further 12,039 ha (19%) of forest land in the SFRL comprise Other State Forests (OSF) owned currently by the FD, excluding the FD owned forest plantations 982 ha (2%) which are also OSF and lie outside gazetted forests. The FD owned OSFs include some of the most biologically valuable forests in the island, such as Neluketiya Mukalana, Kudumeeriya, Karawita Kanda, Ayagama (=Mawarakanda) and Gorangala forests. They would be lost with all their species and genetic resources if circular 2021/02 is followed through, as it requests all forests not specifically gazetted under the Forest Ordinance to be handed over the District Secretaries. 22 MALF (1995). Sri Lanka Forestry Sector Master Plan. Ministry of Agriculture, Lands and Forestry, Sri Lanka 23 Wijesinghe, L C A de S., Gunatilleke, I A U N., Jayawardana, S D G., Kotagama S W and Gunatilleke C V S (1993). Biological Conservation in Sri Lanka. A National Status Report. IUCN, Sri Lanka. 24 DWC unpublished data on Protected Areas, 2019 25 Presidential Policy Directive (2019) “Vistas of Prosperity and Splendour”. NHWA National Heritage Wilderness Area CF Conservation Forest FR Forest Reserve FP-FD (OSF) Forest plantations OSF- FD FD owned Other State Forests OS (F) Other State-owned forests LRC Ownership: Land Reform Commission** PVTF Other privately owned forests PLC F Forests owned by plantation companies U Conservation category unknown Figure 6.8: Conservation categories within forests of the SFRL (by area covered) Source: Data on forest area derived from FD 2015 shape files revised during preparation of the SFR-LMP in 2021 ** being acquired CF 9% FR 40% OSF-FD 19% FP-FD(OSF) 2% OS (F) 1% LRC** 8% PVTF 1% U 0% PLC F 2% NHWA 18% CF FR OSF-FD FP-FD(OSF) OS (F) LRC** PVTF U PLC F NHWA
6. Forests | 61 Introduction to the SFRL 6.5 National significance of forests in the SFRL The biodiversity in the forests of the SFRL and the ecosystem services they render are presented in Section 7 of this document. Figures 6.9 and 6.10 display the individually important forests in the SFRL identified by the NCR to be included in the Minimum Network of Forests needed to conserve Sri Lanka’s full complement of indigenous woody plants and animals, and endemic woody plants and animals respectively. Figure 6.11 depicts the forests in the SFRL identified by the NCR as priority for flood and soil erosion control in Sri Lanka. Of the total 31 forests in the SFRL identified as top priority for conservation of fauna and flora (including endemics), and to control soil erosion and flooding (Annex ST1-A1), 8 are now either NHWA or Conservation Forests, but only part of Auwegalakanda, and Kalubowitiyana are declared as Conservation Forests, and only Habarakada in the contiguous Haycock-Habarakada complex is declared a CF. The prime importance of Haycock has been stressed by Figure 6.9: Individual forests in the SFRL identified by the NCR for inclusion in the minimum network of forests necessary to conserve Sri Lanka’s full complement of woody plants and animals respectively Source: Data from the NCR biodiversity survey depicted in the 2021revised base forest map for the SFRL
6. Forests | 62 Introduction to the SFRL studies carried out in the 1980s,26 and it should be upgraded to CF status/category on its own right. Further, except for Delgoda and Diyadawa, all CFs are under 366 ha (i.e. Habarakada, Auwegalakanda, Magurugoda, Muwagankanda, Massimbula, Kalubowitiyana, Kudumirishena, Delmalla and Thunkadulla kanda, etc.). Further, except for Delgoda (which is within the Sinharaja Rainforest Complex), Auwegalakanda (contiguous with Auwegalakanda FR), Habarakada (contiguous with Haycock FR), and Kalubowitiyana (contiguous with Kalubowitiyana OSF), other CFs transition directly into very different land uses giving rise to sharp edge effects. Notably, of the total area of OSFs in the SFRL, either under the FD or other state agencies, approximately 47% is made up of forest units <200 ha. Several biologically rich OSFs such as Ayagama, Neluketiya Mukalana, and Kudumeeriya that are identified as top priority for conservation of both floral diversity and floral endemics by the NCR have been heavily fragmented over the years. Many also have private land plots issued with permits by the District Secretary, under the powers vested by the Land Commissioner General. A case in point is the Kalugala Forest Reserve which is prioritized by the NCR as nationally important for conserving both woody plant and faunal diversity and endemic fauna. While the NCR was carried out more than 20 years, and many of these forests may have 26 Gunatilleke, IAUN and Gunatilleke, CVS (1984). Distribution of endemics in the tree flora of a lowland hill forest in Sri Lanka. Biological Conservation 28. pp 275-285. Figure 6.10: Individual forests in the SFRL within the Minimum Network of Forests needed to conserve Sri Lanka’s full complement of endemic woody plants and animals respectively Source: Data from the NCR biodiversity survey depicted in the 2021 revised base map for the SFRL